The invention relates to a pantograph mechanism, and more particularly, to a pantograph mechanism which may be used to move a member principally in the vertical direction by means of a linkage.
A pantograph mechanism which is used to support a member such as a microscope on a mount in a manner to be movable vertically usually comprises a linkage as shown in FIG. 1. Specifically, the linkage shown comprises a support member 1 which has its base end 1a mounted on a horizontal portion of a mount and which extends vertically, a holding member 2 disposed in parallel relationship with the support member 1 and adapted to carry a member to be moved on one end 2a ; a link 3 which has one end pivotally connected with end of the holding member 2 and the other pivotally connected to end 1b of the support member 1 by means of pivots 5, 6; and another link 4 which has its ends pivotally connected respectively with a portion of the support member 1 adjacent to the end 1a and with a portion of the holding member 2 adjacent to base end 2b by means of pivots 7, 8. Both support member 1 and holding member 2 comprise arm members. The center axes of the pivots 5, 7 define immovable points O, O' during an angular movement of the links 3, 4 while the center axis of the pivot 6 defines a displaceable point P.
Because the described pantograph mechanism comprises four members, namely, support member 1, holding member 2 and links 3, 4 assembled together to form a parallellogram, it occupies an area S as shown in FIG. 2, and also requires a large area for its operation, presenting difficulties in that its operation may interfere with other parts. When the displaceable point P is to be moved vertically, there results a certain unavoidable degree of lateral or horizontal displacement. To minimize the horizontal displacement and achieve good accuracy in the intended vertical movement, the increased overall size of the mechanism must be increased, thus requiring an even greater occupied area S.